1. Field of the Invention
The present invention relates to a method and apparatus for supplying parts, whose prime object is to supply projection nuts, projection bolts and the like having welding projections reliably to the destination.
2. Prior Art
In such existing apparatus having a telescopic supply rod provided with a guide pin projected at the end, a nut is supplied with the pin extending into a screw hole of the projection nut which is to be supplied, but the nut being supplied is attracted and held by an electromagnet fixed to a stationary member. However, as the supply rod proceeds downwardly the nut becomes more distant from the electromagnet and the electromagnetic force is deteriorated, so that when external forces such as some vibrations are exerted the nut tends to drop imprudently before reaching the destination. Such uncertainty necessitates the pin to be inserted always into the screw hole, and therefore the apparatus is not applicable to a cap nut or lid nut without a through hole. Moreover, though the nut attracting force must be eliminated surely and promptly at a predetermined point of time, when a residual magnetism is present in the supply rod, a reliable operation is not possible as the nut may not come off from the supply rod.
Also an apparatus in which an oil seal is carried to the shaft end so as to be engaged thereto is known, in this case a hollow outer shaft and inner shaft are combined slidably, and the oil seal mounted to the inner shaft end is forcibly transferred to the shaft by the outer shaft which descends alone relatively further after the inner shaft being positioned coaxially with respect to the shaft. However, it is difficult to hold the oil seal accurately at the end of the inner shaft, because inner diameters of the oil seals are slightly different from each other so that the engagement to the inner shaft varies diversely upon each oil seal, slipping out freely in the worst case.
As it will be understood from the foregoing description, objects are to prevent uncertainty of the electromagnet for holding the parts, to ensure the applicability to the parts without through hole and to solve the uncertainty of holding the parts in the supply rod of double construction.